JPH11295932A - Yellow toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To embody excellent heat resistance, sufficient coloring power, transparency and light resistance by incorporating a binder resin and specific condensed azo pigment into a toner. SOLUTION: This toner contains the binder resin and the condensed azo pigment expressed by the formula. The binder resin includes, for example, polyester, polyamide, acrylic resin, etc., for which polyester is more preferable in terms of the possibility of attaining the compatibility of the color developability of the toner with the durability. The content of the polyester is preferably >=70 wt.%, more preferably 90 to 100 wt.% in the binder resin in terms of the assurance of the colorability and the dispersibility of the coloring agents of the toner. Commercially marketed products are usable as the condensed azo pigment expressed by the formula and the amt. thereof to be used is properly determined by the adhesion of the toner set in a copying machine and a printer and is preferably 1 to 20 pts.wt. per 100 pts.wt. binder resin. The average grain size of the resulted yellow toner is 5 to 50 μm, more preferably 7 to 20 μm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a yellow toner used for visualizing a latent image formed on an optical semiconductor in electrophotography, electrostatic recording, and the like.

[0002]

2. Description of the Related Art From the viewpoints of tinting strength, transparency and light resistance, C.I. I. Pigment Yellow 12, 13, 14, 17, and 83 containing a disazo yellow pigment as a coloring agent is used.

[0003] However, the pigments described above have insufficient heat resistance, and yellow toners containing such pigments have a disadvantage that they are easily decomposed during heat fixing.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a yellow toner having excellent heat resistance and sufficient coloring power, transparency and light resistance.

[0005]

The gist of the present invention is to provide a binder resin and a compound represented by the formula (I):

[0006]

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The present invention relates to a yellow toner containing a condensed azo pigment represented by the following formula:

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The yellow toner of the present invention is a toner containing a binder resin and a condensed azo pigment represented by the formula (I).

Examples of the binder resin include polyester, polyamide, acrylic resin, epoxy resin, polycarbonate, polyurethane, silicone resin, fluorine resin, petroleum resin, and natural and synthetic waxes. Polyester is preferred from the viewpoint that both the color developing property and durability of the toner can be achieved. The content of the polyester is preferably 70% by weight or more, and more preferably 90 to 100% by weight in the binder resin, from the viewpoint of ensuring the durability of the toner and the dispersibility of the colorant.

The raw material monomer of the polyester is not particularly limited, and a known polyhydric alcohol component and a polycarboxylic acid component such as carboxylic acid, carboxylic anhydride, and carboxylic acid ester are used.

Examples of the carboxylic acid component include dicarboxylic acids and tricarboxylic acids, specifically, dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, and maleic acid; dodecenyl succinic acid, and octyl succinic acid. Succinic acid, trimellitic acid, pyromellitic acid, anhydrides of these acids, and lower alkyls (1-8 carbon atoms) of those acids substituted with alkyl groups having 20 to 20 or alkenyl groups having 2 to 20 carbon atoms Ester and the like are included, and those containing at least one of these are preferable.

The alcohol component includes, for example,
Polyoxypropylene (2.2) -2,2-bis (4-
(Hydroxyphenyl) propane, polyoxyethylene (2.2) -2,2-bis (4-hydroxyphenyl)
Alkylene oxide (addition mole number 1 to 10) adduct of bisphenol A such as propane, ethylene glycol,
Examples thereof include propylene glycol, glycerin, pentaerythritol, trimethylolpropane, hydrogenated bisphenol A, sorbitol, and etherified polyhydroxyl compounds thereof, and those containing at least one of them are preferable. Further, from the viewpoint of improving the durability of the toner, it is preferable that the alkylene oxide adduct of bisphenol A is used in an amount of 5% by weight or more in the alcohol component.

[0013] The polyester is usually produced by condensation polymerization of an alcohol component and a carboxylic acid component in an inert gas atmosphere, if necessary, using an esterification catalyst at a temperature of 180 to 250 ° C. it can.

The glass transition point of the polyester is 55 to 70.
° C and a softening point are preferably 80 to 150 ° C.

A major feature of the toner of the present invention is that as a colorant, the compound represented by the formula (I):

[0016]

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[0017] A condensed azo pigment excellent in heat resistance represented by the formula (1) is contained.

The content of the condensed azo compound represented by the formula (I) used in the present invention is, for example, "Novoperm Yellow 4".
Commercially available products such as "G" (manufactured by Clariant) can be used.

The amount of the condensed azo pigment represented by the formula (I) is appropriately determined depending on the amount of toner attached in a copying machine and a printer. Preferably it is 20 parts by weight.

The toner of the present invention includes various charge control agents for controlling charge, for example, "Bontron E-84" (manufactured by Orient Chemical Industries) and "LR-1" for negatively chargeable toner.
Chromium-zinc-aluminum-boron complex or salt compound of salicylic acid, benzylic acid or a derivative thereof such as "47" (manufactured by Nippon Carlit); Toners include "Bontron P-51" (manufactured by Orient Chemical Industries), cetyl ammonium bromide, and "COPYCHARGE P-51".
A quaternary ammonium salt such as "SY"; and a copolymer of a nitrogen-containing monomer such as N, N-dialkylaminoethyl (meth) acrylate and N, N-dimethylaminoalkyl (meth) acrylamide.

The toner of the present invention can be prepared by a known method, for example,
The binder resin, the colorant, various internal additives, and the like are uniformly mixed by a known mixer such as a ball mill, and then melt-kneaded by a closed kneader or a single- or twin-screw extruder, and then cooled and pulverized. And a classification method.

Further, on the surface of the toner of the present invention, various external additives such as a fluidity adjusting agent, an anti-filming agent and a cleaning property improving agent may be added.

As described above, the condensed azo pigment represented by the formula (I) is produced by adding a resin to a pigment slurry in the final step of pigment production in addition to mixing with a binder resin at the time of melt-kneading. (Melt flushing method) master batch may be used and mixed.

The thus obtained yellow toner of the present invention has an average particle size of 5 to 50 μm, preferably 7 to 50 μm.
Preferably, it is 20 μm. Here, the average particle diameter is a volume average particle diameter.

The yellow toner of the present invention may be used, for example, in a glass bead carrier, an iron powder carrier, a ferrite carrier, a resin dispersion type carrier or the like having an average particle diameter of 40 to 200 μm.
The yellow developer can be obtained by mixing with a carrier of m using a ball mill or the like. Career
It is preferable that the yellow developer contains 90 to 97% by weight, preferably 94 to 97% by weight.

As a method for forming a yellow image using the yellow toner of the present invention, the two-component developing method using a developer in which a yellow toner and a carrier are mixed, a non-magnetic developing roll, A non-magnetic one-component developing method using a developing device having a blade for applying a charge to a toner by frictional charging while uniformly regulating the thickness of a toner layer formed on the non-magnetic developing roll. Is preferable.

The yellow toner of the present invention can be used in an image forming method for forming a full-color image using a yellow toner, a magenta toner, a cyan toner and a black toner.

As a general method for forming an image of a full-color image, a transfer body system, a tandem system, an intermediate transfer body system,
Examples include a multi-developing multi-rotation system and a multi-developing single pass system. These image forming methods can be applied to the case where the yellow toner of the present invention is used.

The amounts used for mixing the yellow toner, magenta toner, cyan toner and black toner are appropriately selected according to the desired hue.

[0030]

EXAMPLES The glass transition point, softening point, outflow starting temperature, acid value and hydroxyl value of the resin were measured according to the following methods.

[Glass transition point] The glass transition point is measured at a heating rate of 10 ° C./min using a differential scanning calorimeter (DSC210, manufactured by Seiko Instruments Inc.).

[Softening Point and Outflow Starting Temperature] Using a Koka type flow tester (CFT-500, manufactured by Shimadzu Corporation), the temperature at which half of the resin flows out is taken as the softening point, and the resin is melted and the plunger is melted. The temperature at which the temperature begins to drop is defined as the outflow start temperature (sample: 1 g, heating rate: 6 ° C./min, load:
30 kg / cm ² , nozzle: 1 mmφ × 1 mm).

[Acid value and hydroxyl value] JIS K0070
It is measured according to the method according to the above.

Resin Production Example 1 Polyoxypropylene (2.2) -2,2-bis (4-
(Hydroxyphenyl) propane 945 g, fumaric acid 34
8 g and 13 g of dibutyltin oxide as an esterification catalyst were reacted with stirring at 210 ° C. under a nitrogen stream. The obtained resin is referred to as polyester A. Polyester A has a glass transition point of 60 ° C., a softening point of 101.2 ° C., an outflow starting temperature of 78.3 ° C., and an acid value of 20.0 (KOHmg /
g), and the hydroxyl value was 18.4 (KOHmg / g).

Resin Production Example 2 Polyoxypropylene (2.2) -2,2-bis (4-
Resin Preparation Example 1 The reaction was carried out in the same manner as described above.
Let the obtained resin be polyester B. Polyester B
Has a glass transition point of 65 ° C., a softening point of 107.2 ° C., an outflow starting temperature of 79.8 ° C., and an acid value of 27.8 (KOHmg /
g), and the hydroxyl value was 15.1 (KOHmg / g).

Example 1 70 parts by weight of polyester A and a condensed azo pigment represented by the formula (I) (manufactured by Clariant, "Novoperm Yellow 4")
G ") 30 parts by weight were melt-kneaded using a pressure kneader to produce a pigment master batch.

Next, 81 parts by weight of polyester A, 15 parts by weight of master batch and 4 parts by weight of Bontron E-84 (manufactured by Orient Chemical Industries) are melt-kneaded by a twin-screw extruder, and then pulverized and classified to obtain an average particle diameter of 7 parts. 0.5 μm yellow particles were obtained. To 100 parts by weight of the yellow particles, 0.5 parts of hydrophobic silica (H-2000, manufactured by Wacker Chemical Company) is used.
By weight, a yellow toner was obtained.

5 parts by weight of the obtained yellow toner was mixed with 95 parts by weight of a ferrite carrier having an average particle diameter of 50 μm coated with a silicone resin in a ball mill to obtain a yellow developer.

The obtained yellow developer was applied to Pretail 55
0 (manufactured by Ricoh Co., Ltd.) and a printing test was carried out. As a result, a good yellow image was obtained stably from the initial stage to 10,000 sheets.

The obtained yellow image was subjected to an exposure light resistance test for 8 hours using a weather meter. The color tone change was ΔE = 1.5, and almost no fading was observed. Furthermore, a solid yellow print is made on the Kao OHP sheet, and SZ- # 80 (manufactured by Nippon Denshoku Industries Co., Ltd.)
As a result of measuring the light transmittance using, the transmittance was 80%.

Example 2 70 parts by weight of polyester B and 30 parts by weight of a condensed azo pigment represented by the same formula (I) as in Example 1 were melt-kneaded using a pressure kneader to produce a pigment master batch. did.

Next, 84 parts by weight of polyester B, 15 parts by weight of master batch and 1 part by weight of LR-147 (manufactured by Nippon Carlit) were melt-kneaded by a twin screw extruder.
After pulverization and classification, yellow particles having an average particle size of 9.5 μm were obtained. To 100 parts by weight of the yellow particles, 0.5 parts by weight of hydrophobic silica (R-972, manufactured by Nippon Aerosil Co., Ltd.) was added to obtain a yellow toner.

The obtained yellow toner was mounted on Page Presto N-4 (manufactured by Casio Computer Co., Ltd.), which is a non-magnetic one-component developing system, and a printing test was carried out. It was obtained until stable. The light transmittance was measured in the same manner as in Example 1, and as a result, the light transmittance was 80%.

Reference Example 1 In Example 1, instead of the condensed azo pigment represented by the formula (I), C.I. I. Pigment Red 57: 1 (Sumika Print Carmine 6BC-4, manufactured by Sumitomo Chemical Co., Ltd.)
50) to prepare a masterbatch and then
A magenta developer was prepared in the same manner as in Example 1 except that the mixture was melt-kneaded with the following composition.

Polyester A 78 parts by weight Masterbatch 18 parts by weight Bontron E-84 (manufactured by Orient Chemical Industries) 4 parts by weight

Reference Example 2 In Example 1, C.I. was substituted for the condensed azo pigment represented by the formula (I). I. Pigment Blue 15: 3 (manufactured by Sanyo Dyeing Co., Ltd., Cyanine Blue KRS) was used to prepare a masterbatch, and then melt-kneaded with the following composition, except that it was melt-kneaded in the same manner as in Example 1 to obtain a cyan developer. did.

Polyester A 84 parts by weight Masterbatch 12 parts by weight Bontron E-84 (manufactured by Orient Chemical Industries) 4 parts by weight

Reference Example 3 94 parts by weight of polyester A, 4 parts by weight of carbon black (Mogal L, manufactured by Cabot Corporation) and Bontron E-8
4 (manufactured by Orient Chemical Industries) was melt-kneaded with a twin-screw extruder, and then pulverized and classified to have an average particle size of 8.5.
μm black particles were obtained. Hydrophobic silica (H-200, manufactured by Wacker Chemical Co., Ltd.) was used for 100 parts by weight of the black particles.
0) A black toner was obtained by adding 0.5 parts by weight.

5 parts by weight of the obtained black toner was mixed with 95 parts by weight of a ferrite carrier having an average particle diameter of 50 μm coated with a silicone resin in a ball mill to obtain a black developer.

Test Example The yellow developer obtained in Example 1 was combined with the magenta developer, cyan developer and black developer obtained in Reference Examples 1 to 3 to prepare Pretail 550 (manufactured by Ricoh Co., Ltd.). A good full-color image was obtained as a result of mounting and a printing test.

From the above results, the yellow toners obtained in Examples 1 and 2 have excellent heat resistance and contain the condensed azo pigment represented by the formula (I). It can be seen that the toner is excellent in light fastness, and that a good yellow image and a full-color image can be obtained using such a yellow toner.

[0052]

According to the present invention, it is possible to provide a yellow toner which is excellent in heat resistance and has sufficient coloring power, transparency and light resistance. Further, by using the yellow toner of the present invention, a good yellow image and a full-color image can be obtained.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Eiji Shirai 1334 Minato, Wakayama

Claims (2)

[Claims] 1. A binder resin and a compound represented by the formula (I): A yellow toner containing a condensed azo pigment represented by the formula: 2. The method according to claim 1, wherein the binder resin is polyester.
The yellow toner described in the above.